body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
max-width: 800px;
margin: 0 auto;
padding: 20px;
}
.calculator-container {
background-color: #f9f9f9;
border: 1px solid #e0e0e0;
border-radius: 8px;
padding: 30px;
margin-bottom: 40px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.calculator-title {
text-align: center;
margin-bottom: 25px;
color: #2c3e50;
font-size: 24px;
font-weight: 700;
}
.input-group {
margin-bottom: 20px;
}
.input-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #555;
}
.input-group input {
width: 100%;
padding: 12px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.input-group .help-text {
font-size: 12px;
color: #777;
margin-top: 5px;
}
.calc-btn {
display: block;
width: 100%;
padding: 14px;
background-color: #0056b3;
color: white;
border: none;
border-radius: 4px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.2s;
}
.calc-btn:hover {
background-color: #004494;
}
#result-container {
margin-top: 25px;
padding: 20px;
background-color: #fff;
border: 1px solid #ddd;
border-radius: 4px;
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
padding-bottom: 10px;
border-bottom: 1px solid #eee;
}
.result-row:last-child {
border-bottom: none;
margin-bottom: 0;
}
.result-label {
font-weight: 500;
}
.result-value {
font-weight: 700;
color: #2c3e50;
}
.final-rate {
font-size: 28px;
color: #27ae60;
text-align: center;
margin-top: 15px;
font-weight: 800;
}
.article-content h2 {
color: #2c3e50;
margin-top: 30px;
border-bottom: 2px solid #eee;
padding-bottom: 10px;
}
.article-content h3 {
color: #34495e;
margin-top: 20px;
}
.article-content ul {
margin-bottom: 20px;
}
.article-content li {
margin-bottom: 10px;
}
.alert {
padding: 15px;
background-color: #fff3cd;
border: 1px solid #ffeeba;
color: #856404;
border-radius: 4px;
margin-bottom: 20px;
}
function calculateFarRate() {
// 1. Get DOM elements
var inputTotalIndirect = document.getElementById('totalIndirectExpenses');
var inputUnallowable = document.getElementById('unallowableCosts');
var inputDirectLabor = document.getElementById('directLaborBase');
var resultContainer = document.getElementById('result-container');
// 2. Parse values
var totalIndirect = parseFloat(inputTotalIndirect.value);
var unallowable = parseFloat(inputUnallowable.value);
var directLabor = parseFloat(inputDirectLabor.value);
// 3. Handle default/empty values
if (isNaN(totalIndirect)) totalIndirect = 0;
if (isNaN(unallowable)) unallowable = 0;
if (isNaN(directLabor)) directLabor = 0;
// 4. Validate Logic
if (directLabor <= 0) {
alert("Direct Labor Base must be greater than zero to calculate a rate.");
return;
}
// 5. Calculate
// Net Allowable Overhead = Total Indirect – Unallowable
var allowableOverhead = totalIndirect – unallowable;
// Rate = (Net Allowable / Direct Labor Base) * 100
var overheadRate = (allowableOverhead / directLabor) * 100;
// 6. Format Output
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
});
document.getElementById('resTotalIndirect').innerText = formatter.format(totalIndirect);
document.getElementById('resUnallowable').innerText = formatter.format(unallowable);
document.getElementById('resAllowable').innerText = formatter.format(allowableOverhead);
document.getElementById('resBase').innerText = formatter.format(directLabor);
document.getElementById('resFinalRate').innerText = overheadRate.toFixed(2) + "%";
// 7. Show Results
resultContainer.style.display = "block";
}
How to Calculate FAR Overhead Rate for Government Contracts
For architecture, engineering, and construction firms looking to secure contracts with federal or state agencies (such as State DOTs), understanding the FAR (Federal Acquisition Regulation) Overhead Rate is critical. This rate determines how much a firm can be reimbursed for indirect costs relative to their direct labor on government projects.
The calculation follows strict guidelines set forth in FAR Part 31, which dictates the allowability of costs. An accurate overhead rate ensures compliance, helps in competitive bidding, and maximizes cost recovery.
The FAR Overhead Rate Formula
The standard formula for calculating the overhead rate is:
Overhead Rate = (Net Allowable Indirect Costs / Direct Labor Base) × 100
Where:
- Net Allowable Indirect Costs: The total indirect expenses (overhead pool) minus any "unallowable" costs.
- Direct Labor Base: The total gross salaries and wages of employees utilized directly on projects.
Step-by-Step Calculation Guide
1. Determine the Indirect Cost Pool
Indirect costs are expenses incurred for the general operation of the business that are not directly chargeable to a specific project. Common examples include:
- Office Rent and Utilities
- General Liability Insurance
- Administrative and Clerical Salaries (Indirect Labor)
- Software Subscriptions and IT Support
- Depreciation of Assets
- Employee Fringe Benefits (if not calculated as a separate rate)
2. Remove Unallowable Costs (FAR Part 31)
This is the most critical step for compliance. The government will not reimburse certain "unallowable" expenses. These must be subtracted from your indirect pool before calculating the rate. Common unallowable costs include:
- Entertainment: Tickets to events, social activities.
- Bad Debts: Uncollected accounts receivable.
- Interest: Interest on borrowing (though cost of money may be allowable).
- Contributions & Donations: Charitable giving.
- Alcoholic Beverages: Strictly prohibited.
- Federal Income Taxes: Not an allowable cost.
- Advertising: Specifically for promoting the business (with some exceptions for recruitment).
3. Calculate the Direct Labor Base
Your denominator is the Direct Labor Base. This represents the salaries of employees while they are working on revenue-generating projects. It is crucial to separate Direct Labor from Indirect Labor (e.g., time spent on marketing, admin, or training).
Example Calculation
Let's assume an engineering firm has the following financial data for the fiscal year:
- Total Indirect Expenses: $1,200,000
- Identified Unallowable Costs: $50,000 (Entertainment, Interest, etc.)
- Direct Labor Costs: $800,000
Step 1: Calculate Allowable Indirect Pool
$1,200,000 – $50,000 = $1,150,000
Step 2: Apply the Formula
($1,150,000 / $800,000) × 100 = 143.75%
This means for every $1.00 of direct labor charged to a government project, the firm can charge an additional $1.4375 to cover overhead expenses.
Why This Matters for Audits
Government agencies frequently audit these rates. If you fail to remove unallowable costs, your rate may be adjusted downward during an audit, potentially leading to a requirement to pay back previously reimbursed funds. Maintaining a clean General Ledger with accounts specifically segregated for "unallowable" expenses simplifies the calculation and audit process.